Pickup trucks currently represent a substantial proportion of the vehicles on American roads, particularly in the southwestern part of the country. They are particularly suitable for cargo hauling via the truck bed in which the cargo can be either covered for weather protection or uncovered and exposed to the elements. Depending on the shape and height of the cargo it can be load locked or tied down by use of straps that are frequently resorted to in the course of hauling. The typical truck bed is about 50-60 inches in width and less than about 97 inches in length.
The use of a bed cover termed a "tonneau" when utilized overlies the bed and is commonly employed for weather protection of the cargo. A tonneau installation typically requires a plurality of intersecting rails by which the tonneau cover is supported. Snaps secure the cover in place. Use of the bed for tie down when required and/or load lock without the cover usually involves disassembly and removal of rails and related components supporting the cover and installation of alternate components for these applications. These units must subsequently be re-interchanged when the cover is to be re-installed. Typically, two persons are required to remove and install the tonneau cover. Yet failure to remove the cover support system, when alternative uses of the truck bed are contemplated, severely limits the cargo hauling capacity of the truck. A form of tonneau cover installation is disclosed in U.S. Pat. No. 4,757,854.